Role of multidetector ct in quantitative enhancement- washout analysis of solid renal masses

Background Enhancement washout technique in solid renal masses using multidetector computed tomography (MDCT) can differentiate different type of lesions. 99 Patients who are presenting with suspected renal masses or renal tumour for staging are included in this study. CT examination are carried out at urology and nephrology centre using MDCT. The attenuation values (Hounsfield Unit) will be assesed for each lesion on the pre enhanced, corticomedullary, nephrographic and delayed phases. Washout ratio will be calculated for each phase of enhancement in comparison to the unenhanced attenuation value. The characteristics of enhancement-washout will be correlated with the final histopathological diagnosis. Results Early enhancement and washout pattern was noted in 54 renal lesions (54.5%) representing 4 types of renal lesions; Oncocytoma (n = 13), clear cell renal cell carcinoma (n = 16), Chromophobe renal cell carcinoma (n = 15) and unclassified renal cell carcinoma (n = 10).Prolonged enhancement pattern was noted 45 lesions (45.4%); PRCC (n = 14), 10 case of lipid poor AML (n = 10), metanephric adenoma (n = 10) and Xp11 RCC (n = 11). High pre-contrast attenuation was noted in Xp 11RCC showing attenuation value 41.7 ± 6.823HU. The highest CMP values were noted in CCRCC (151.9 ± 20.4) followed by oncocytomas (137.6 ± 19.15HU) and then CHRCC (123.6 ± 16.6 HU)while the lowest values were noted in Metanephric adenoma)57.1 ± 17.4HU)and followed by PRCC (59.9 ± 4.8)and followed by lipid poor AML (79.17 ± 13.666) and RCC unclassified (89.06 ± 18.1). Conclusions Four-phase MDCT (the unenhanced, corticomedullary, nephrographic, and excretory phases) evaluate role of MDCT in differentiation of solid renal masses.

Metanephric Adenoma Associated with Unusual Urinary Candidiasis: A Challenging Morbidity from Postoperative Anastomotic Leak

Metanephric adenoma (MA) of the kidney is a rare benign neoplasm, which is mostly incidental-discovered during imaging studies for other clinical problems. However, this tumor may overlap in morphology with the papillary renal cell carcinoma and there are descriptions of metastatic disease. To date, fewer than 200 cases of MA have been reported worldwide and usually have a good prognosis. In the current report, a case of MA in a middle-aged lady is presented, which developed postoperative morbidity resulting from prolonged perinephric leakage secondary to urinary and perinephric fungus infection as a part of systemic candidiasis. The clinical, morphological and immunohistochemical features are presented together with a review of the current literature.

Metanephric Adenoma: A Case Report of a Rare Benign Renal Tumor

Introduction: Metanephric adenoma (MA) is a rare benign kidney tumor with an excellent prognosis, which is usually diagnosed incidentally with no symptoms. The mean age of patients with MA is about 41 years, ranging from 5 months to 83 years in previous studies. Case Presentation: In this study, we present the case of a 29-year-old woman with a diagnosis of MA after nephrectomy. The ultrasound study showed a hyperechoic mass. The intravenous (IV) contrast-enhanced abdominopelvic computed tomography (CT) scan showed a hypodense mass. Based on the results of pathological features and immunohistochemistry (IHC) (positive vimentin, WT1, and PAX8), the diagnosis of MA was established. Conclusions: The diagnosis of MA is commonly based on pathological findings. Therefore, if MA is suspected, renal biopsy, partial nephrectomy, or follow-up of the patient can be used. However, further studies are needed to differentiate MA from papillary renal cell carcinoma and nephroblastoma before taking aggressive measures.

Retrospective evaluation of our percutaneous biopsy results of renal masses

Objective: In this study, we aim to present the retrospective results of percutaneous biopsies performed on solid kidney lesions in our clinic with the literature. Materials and Methods: In this retrospective descriptive study approved by the ethics committee in our center, the demographic features and histopathological results of 57 patients who had a solid mass in the kidney between 2017-2020 and underwent ultrasonography-guided percutaneous kidney biopsy in our interventional radiology clinic were analyzed from the hospital database. Patients without pathology results were excluded from the study. Results: Our patients consisted of 35 men (61,4%) and 23 women (38,6%). The average age was 59.02±15.33(6-94). We had 1 child and 56 adult patients. 29 of the kidney lesions were located in the left kidney(50,9%) and 28 were located in the right kidney(49,1%). In 44 patients(77.2%) who had malignant pathology; the results were 41 renal cell carcinoma(93.2%), 2 lung squamous cell carcinoma metastasis(4.5%) and 1 primary metastatic pleomorphic adenoma of the salivary gland(2.3%). In a total of 13 patients(22.8%) whose pathology results were benign; the results were 5 oncocytomas(38.5%), 5 angiomyolipoma(38.5%), 2 chronic pyelonephritis(15.4%) and 1 metanephric adenoma(7.6%). Renal cell carcinoma rate was 71.9% among all lesions. Conclusion: Radiological methods may not provide sufficient diagnostic data in the differential diagnosis of solid renal masses.In our study, the rates of benign lesions as a result of percutaneous biopsy were higher compared to the literature. Therefore, we believe that it is remarkable in terms of the importance of preoperative biopsy in solid lesions. Keywords: renal mass, percutaneous biopsy, renal cell carcinoma

Metanephric adenoma with BRAF V600K mutation and a doubtful radiological imaging: pitfalls in the diagnostic process

Metanephric adenoma (MA) is an uncommon benign renal tumor whose histomorphological aspect resembles that of Wilms’ tumor and papillary renal cell carcinoma. From a diagnostic and therapeutic perspective, recognition of this entity is important as it has a more favorable clinical outcome compared with Wilms’ tumor and papillary renal cell carcinoma. MA should not be treated with nephrectomy if the tumor size is small, opting for a conservative treatment. However, the preoperative diagnosis of this disease is extremely challenging. The present study describes a case of this rare disease, showing an ambiguous radiological imaging and that only after a percutaneous biopsy, was defined as a MA and treated with partial nephrectomy. Moreover, the histological diagnosis of this case was partially complicated by the equivocal immunohistochemical analysis showing negativity for BRAF VE1 staining. Only the mutational analysis demonstrated the presence of the BRAF V600K mutation (for the first time described in a case of metanephric adenoma), highlighting the necessity of sequencing in case of MA with negativity for BRAF VE1 clone.

KANK1-NTRK3 fusions define a subset of BRAF mutation negative renal metanephric adenomas

Background Metanephric adenoma (MA) is a rare benign renal neoplasm. On occasion, MA can be difficult to differentiate from renal malignancies such as papillary renal cell carcinoma in adults and Wilms̕ tumor in children. Despite recent advancements in tumor genomics, there is limited data available regarding the genetic alterations characteristic of MA. The purpose of this study is to determine the frequency of metanephric adenoma cases exhibiting cytogenetic aberration t (9;15)(p24;q24), and to investigate the association between t (9,15) and BRAF mutation in metanephric adenoma. Methods This study was conducted on 28 archival formalin fixed paraffin-embedded (FFPE) specimens from patients with pathologically confirmed MA. Tissue blocks were selected for BRAF sequencing and fluorescent in situ hybridization (FISH) analysis for chromosomal rearrangement between KANK1 on chromosome 9 (9p24.3) and NTRK3 on chromosome 15 (15q25.3), which was previously characterized and described in two MA cases. Results BRAFV600E mutation was identified in 62% of our cases, 9 (38%) cases were BRAFWT, and 4 cases were uninformative. Of the 20 tumors with FISH results, two (10%) were positive for KANK1-NTRK3 fusion. Both cases were BRAFWT suggesting mutual exclusivity of BRAFV600E and KANK1-NTRK3 fusion, the first such observation in the literature. Conclusions Our data shows that BRAF mutation in MA may not be as frequent as suggested in the literature and KANK-NTRK3 fusions may account for a subset of BRAFWT cases in younger patients. FISH analysis for KANK1-NTRK3 fusion or conventional cytogenetic analysis may be warranted to establish the diagnosis of MA in morphologically and immunohistochemically ambiguous MA cases lacking BRAF mutations.